Module-Body Control: Notes

WARNING: This page is about a different car, the 2008 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.

The Body Control Module (BCM) (also known as the Signal Acquisition and Actuation Module/SAM) monitors many hard wired switch and sensor inputs as well as those resources it shares through electronic message communication over the Controller Area Network (CAN) data bus with other electronic modules in the vehicle. The internal programming and all of these inputs allow the BCM to determine the tasks it needs to perform and their priorities, as well as both the standard and optional features that it should provide. The BCM then performs those tasks and provides those features through both electronic message communication over the CAN data bus with other modules and hard wired outputs through a number of driver circuits, relays, and actuators. These many outputs allow the BCM the ability to control numerous accessory systems in the vehicle.

The BCM will store fault information in the form of a Diagnostic Trouble Code (DTC) or a hexadecimal number attributed to a DTC in BCM memory if a malfunction is detected. Any stored DTC or hexadecimal number can be retrieved using a diagnostic scan tool.

The hard wired circuits between components related to the BCM may be diagnosed using conventional diagnostic tools and procedures. Refer to SYSTEM WIRING DIAGRAMS . The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the BCM or the electronic controls or communication between modules and other devices that provide some features of the BCM. The most reliable, efficient, and accurate means to diagnose the BCM or the electronic controls and communication related to BCM operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.